The purpose of the proposed study is to examine risk factors for occupational back pain (OBP), and to examine the impact of work disability on workers and their co-workers in a large population population (n = 12,500) of health care workers at Duke University Medical Center (DUMC). This study aims to examine organizational factors, such as downsizing efforts while considering other known and suspected risk factors of OBP, as possible predictors for back injury and disability in health care workers that have not been adequately addressed in prior studies. In addition, risk factors for back injury specific to nursing personnel whose jobs involve patient handling will be examined. Detailed analyses will be conducted to explore differences in back injuries that result in restricted and lost workdays across variable demographic, psychosocial, and occupational characteristics for the entire cohort of health care workers. Factors influencing the feasibility and effectiveness of modified work assignments specific to nursing units will also be addressed. The number of lost and restricted workdays, physical impairment, psychosocial demands, and the injured worker's perception of workplace accommodations will be considered in determining the overall effectiveness of modified work assignments. The feasibility of modified work assignments in nursing units will be examined by considering feedback from nurse managers, nursing personnel, occupational physicians, occupational health nurses, and workers' compensation administrators and case-managers who are integrally involved with implementing these workplace strategies. Data previously collected at DUMC will be used, as well as additional prospective surveillance data, and focus group information. This mix of quantitative and qualitative techniques will be utilized to address the National Occupational Research Agenda's Priority Research Area of low back disorders, in addition to addressing issues related to special populations at risk, surveillance efforts, and occupational health services research.